Remote visual examination apparatus

ABSTRACT

A remote visual examination apparatus for viewing reactor internals having a TV camera with a self-contained lighting system and remote focus is extended from a mast which is remotely positionable through particularly placed openings in the reactor core support barrel flange. A pivotal mast vernier elevation and rotation unit rides on the core support barrel flange and serves to control the ultimate elevational and rotational positioning of the mast to orient the TV camera with respect to the particular internal to be viewed. The camera is fixed to the end of the mast by means of a pneumatically actuated tilt assembly which may be remotely controlled to tilt the camera so as to extend the range of view thereof.

United States Patent [1 1 Kosky et al.

[ REMOTE VISUAL EXAMINATION APPARATUS [75] Inventors: Richard P. Kosky,East Granby,

Conn.; Preston W. Averill, Springfield, Mass.

[73] Assignee: Combustion Engineering, Inc.,

Windsor, Conn.

[22] Filed: Mar. 3, 1971 [21] Appl. No.: 120,569

[52] US. Cl. 178/7.81, l78/DIG. 1 [51] Int. Cl. H04n 5/26 [58] Field ofSearch l78/DIG. l, DIG. 38,

178/78, 7.81, DIG. 30; 95/86; 352/243; 248/157, 425; 52/115, 116

[56] References Cited Oct. 9, 1973 1,088,226 10/1967 Great Britain178/DIG. 30

Primary Examiner-Robert L. Griffin Assistant Examiner-Joseph A. Orsino,Jr. Att0rneyCarlton F. Bryant, Stephen A. Schneeberger, Eldon l-l.Luther, Robert L. Olson,

John F. Carney, Richard H. Berneike and Lawrence R. Kessler [57]ABSTRACT A remote visual examination apparatus for viewing reactorinternals having a TV camera with a selfcontained lighting system andremote focus is extended from a mast which is remotely positionablethrough particularly placed openings in the reactor core support barrelflange. A pivotal mast vernier elevation and rotation unit rides on thecore support barrel flange and serves to control the ultimateelevational and rotational positioning of the mast to orient the TVcamera with respect to the particular internal to be viewed. The camerais fixed to the end of the mast by means of a pneumatically actuatedtilt assembly which may be remotely controlled to tilt the camera so asto extend the range of view thereof.

10 Claims, 7 Drawing Figures PATEHTEDHBT 91975 7 3,764,736

SHEET 10F 4 INVENTORS R. P. KOSKY P. WAVERILL, Jr.

ems ,764J36 PATENTED Um SHEET 3 OF 4 3 FIG. 3

INVENTORS R. P. KOSKY P. W. AVERILL, Jr

4 I973 PATENTEU 9 SHEUMF 4 3,764,736

FIG.6

Fl 5 INVENTORS R. P. KOSKY P.W. AVERILL, Jr.

1 REMOTE VISUAL EXAMINATION APPARATUS BACKGROUND OF THE INVENTIONNuclear reactor facilities, which are now being extensively adopted tomeet the rapidly growing power require'ments in this country, are beingsubjected to high safety standards because of the public fear of releaseof dangerous fission products in the event of a major reactormalfunction. In order to comply with the stringent safety standards,reactor facility imspection programs are being developed which includeboth initial (or base line) inspection of the various reactor componentsand periodic in-service inspection to determine the continuingstructural integrity of the facility at various times in the lifethereof. The inspection programs set forth an agenda for both visual andvolumetric examination of reactor internals, including for example thepressure vessel, the core stabilizing lug-to-vessel welds, vesselcladding, fuel bundles, thermal shield, and the core support barrel.

The base line inspection is made before the reactor goes into service toensure safe start-up operation as well as to provide an initialreference point for future testing of each element. The continuingperiodic inspection is necessary in that the fundamental components ofthe reactor facility are subjected to extreme environmental conditionsapproximating 2,500 psi and 650F as well as irradiation; theseconditions being, of course, highly detrimental to the materialsinvolved.

Even though the periodic inspection is carried out during regularreactor servicing shutdown times, direct visual examination is notpossible due to the radiation of the internals. Therefore, inspectionapparatus has been developed which is remotely controlled from thereactor refueling machine (application Ser. No. 886,231 filed Dec. 18,1969 now U.S. Pat. No. 3,664,922, in the name of G. A. Diwinsky et al.).This apparatus is, however, limited in that examination of the pressurevessel requires removal of the reactor internals. If the core supportbarrel is to remain withiri the pressure vessel during a particularinspection period, it is not possible to inspect that area between thecore support barrel and the pressure vessel with this apparatus due tospace limitations.

SUMMARY OF THE INVENTION There is herein provided an apparatus forremote visual examination of reactor internals and, more particularly,an apparatus for examination of the formerly inaccessible area betweenthe core support barrel and the pressure vessel. A TV camera with aself-contained lighting system and remote focus is extended from a mastwhich is positionable through particularly placed openings in thereactor core support barrel flange. A pivotable mast vernier elevationand rotation unit rides on the core support barrel flange and serves tocontrol the ultimate elevational and rotational positioning of the mastto orient the TV camera with respect to the particular internal to beviewed. The camera is fixed to the end of the mast by means of apneumatically actuated tilt assembly which may be remotely controlled totilt the camera so as to extend the range of view thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of areactor vessel and associated core support barrel with the remoteexamination device of this invention positioned therebetween.

FIG. 2 is a side elevational view of the pivotable vernier elevation androtation unit along the line 2-2 of FIG. 4.

FIG. 3 is a side elevational view of the pivotable mast vernierelevation and rotation unit along the line 3-3 of FIG. 4.

FIG. 4 is a plan view of the pivotable mast vernier elevation androtation unit according to this invention.

FIG. 5 is a side elevational view of the remote viewing TV camera andthe tilt mechanism therefor.

FIG. 6 is a side elevational view of the TV camera and tilt mechanismalong the line 6-6 of FIG. 5.

FIG. 7 is a plan view of the remote visual examination mast along theline 77 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now the the drawings,FIG. 1 shows a remote visual examination apparatus 10 for visuallyexamining nuclear reactor internals. The remote visual examinationapparatus 10 is used to particularly examine the area between thepressure vessel 12 and the core support barrel located therewithin, butmay also be used to inspect beneath the reactor core or the core fuelbundles. The core support barrel 30 has acce'ss holes 32 placed atparticular strategic points in the (not shown) to position the coresupport barrel 30 within the pressure vessel 12. The core support barrel30 has stabilizing lugs 36 (one shown) located between the pressurevessel 12 and the barrel 30 adjacent the lower portion of the barrel soas to maintain the spacing thereof relative to the housing of the vessel12. Beneath the core support barrel 30 are core stop lugs 38 (one shown)which position the core relative to the bottom of the pressure vessel 12in the unlikely event the core should fall. A thermal shield 40 may belocated between the core support barrel 30 and the pressure vessel 12adjacent the reactive core area to provide additional shielding againstthermal radiation.

A pivotable mast vernier elevation and rotation unit 42 (seeparticularly FIGS. 2, 3 and 4) rides on the core support barrel flange34 overlying the access holes 32. This elevation and rotation unit 42provides ultimate control actions for a remote visual examinationapparatus mast 28 when the mast is inserted in its operating positionbetween the core support barrel 30 and the pressure vessel 12 throughthe access holes 32. The

pivotable mast vernier elevation and rotation unit 42 comprises a base44 having ball casters 46 fixed to the underside thereof to permit freemovement of the unit 42 on the flange 34. The base 44 has a firstsupport 48 for the mounting of a rotating base 50. The rotating base 50carres a chain sprocket 52 and is mountd in a thrust bearing 54 fixed tothe first support 48.

The rotating base 50 carries tilting base bearings 56 to which a tiltingbase 58 is pivotally joined by means of tilting base legs 60. On thetilting base 58 is a spur gear 62 mounted on a shaft 64, the shaft 64having the supports 66 therefor fixed to the base 58. At one end of theshaft 64 is a worm gear 68 which meshes with an elevational adjustmentactuator gear 70 driven by an elevational adjustment actuator 72.

Fixed to one side of the remote visual examination apparatus mast 28 isa driving rack 74 which is engaged with the spur gear 62 to be driventhereby for selective elevational adjustment of the mast 28. On theopposite side of the mast 28 is a rack 76 which is engaged by a followergear 78 mounted for rotation on the tilting base 58 by means of asupport 80. The follower gear 78 serves to counter the reactive forcesof the gear 62 on the mast 28. To provide lateral support for the mast28 support rollers 82 fixed to the tilting base 58 by means of supports84 engage opposite edges of the mast 28.

The base 44 of the pivotable mast vernier elevation and rotation unit'42 has additionally mounted thereon a second support 86 upon which adrive sprocket 88 is carried by a shaft 90 rotatably fixed to thesupport 86. The shaft 90 has a first miter gear 92 fixed to one endthereof engaging a second miter gear 94 mounted on a shaft 96 rotatablycarried by the support 86, the shaft 96 also supporting a worm gear 98.The worm gear 98 is engaged by a rotational adjustment actuator gear 100which. in turn, is actuated by a rotational adjustment actuator 102 forselective rotational adjustment of the mast 28. A sprocket chain 104 ispositioned about the drive sprocket 88 and chain sprocket 52 to providethe driving rotational force for the remote visual examination apparatusmast 28.

The remote visual examination apparatus mast 28 is formed in an Hconfiguration (see FIGS. 5, 6 and 7) having broad sides 106 connected bya web 108. The H configuration provides flexibility in one lateraldirection to permit flexing on insertion into the cavity of the vessel12, while providing ridigity in the other lateral direction to allowremote horizontal adjustment to be described hereinbelow. The racks 74and 76 are fixed to the sides 106 while the lateral support rollers 82engage the feet of the broad sides 106 to provide motive force andsupport for the mast 28.

Tilt mechanism housing sides 110 are connected to and extend beyond theend of the mast 28 (in particular see FIG. 6) so as to accommodate thetilt mechanism for the remote visual equipment. Pins 112 extendingthrough the sides 110 support air cylinders 114 having air lines 116connected to the opposite ends of the cylinders 114 so as to permit thecylinders to be double acting. The airlines 116 extend upward throughthe H configuration of the mast 28 so that they are readily accessibleas well as being protected thereby. Piston rods 118 of the air cylinders114 are connected to a tilt direction control arm 120 which in turn isconnected to actuating arms 122 by pins 124 which extend through slots126 in sides 110. The actuating arms 122 are connected to pviot arms 128which, in turn, have a fixed pivot point 130 about the ends of the sides110. The slots 126 control the extension of the piston rods 118 which,in turn, determine the minimum angle between the actuating arms 122 andthe pivot arms 128 to control the position of a TV camera 132. Thecamera 132 has a bullet nose to facilitate insertion into the cavity ofthe pressure vessel 12 and help guide it around the thermal shield 40.It is connected to the pivot arms 128 by means of a mounting collar 134.The camera 132 which has a self-contained lighting system and-remotefocusing may have an opening 138 so as to provide a viewing angle A atright angles thereto or maybe designed for straight ahead viewing. Acable 140 for the camera 132 passes through control arm 120 and betweenair cylinder l14before extending up through the H portion of the mast 28on the opposite side of the web 108 from the air lines 116 so as tosimilarly be protected by the H configuration of the mast 28.

The operation of the remote visual examination apparatus 10 is asfollows. The reactor vessel closure head (not shown) is removed and theremote visual examination apparatus mast 28 is manipulated from a remoteposition above the reactor vault, such as from the refueling machinebridge, so that the remote visual examination apparatus 10 is adjacent adesired access hole 32 in the flange 34 of the core support barrel 30.The pivotable mast vernier elevation and rotation unit 42 is attached tothe remote visual examination apparatus mast 28, and lowering of themast 28 through the selected access hole 32 into the cavity of thepressure vessel 12 is initiated. It is noted that the apparatus 10 isdesigned specifically for use with the fuel (not shown), core supportbarrel 30 and thermal shield 40 remaining in the vessel but they may beremoved if desired.

The mast 28 is lowered to a level at which the driving rack 74 engagesthe spur gear 62. At this point vertical elevation is controlled by theelevational adjustment actuator 72 which may be manipulated by a remotehandling tool (not shown) so as to provide accurate elevationaladjustment of the remote visual examination apparatus 10. When theexamination apparatus 10 is substantially at its desired elevationallevel, proper rotational orientation is accomplished through actuationof the rotational adjustment actuator gear by the rotational adjustmentactuator 102, the actuator 102 being manipulated by a remote handlingtool such as that used to control the elevational control actuator 72.During the elevational and rotational adjustment, the follower gear 78and the support rollers 82 serve to sta bilize the mast 28. If it isdetermined that, in addition to the elevational and rotationalpositioning of the remote visual examination apparatus 10, horizontalmovement of the apparatus 10 is necessary to obtain a desired view of aparticular reactor internal to be examined, such horizontal movement maybe accomplished by horizontal movement of the mast 28 at the remoteworking level, such as the refueling machine bridge, in the directionopposite to the desired movement. The resultant horizontal movement ofthe apparatus 10 is possible due to the fact that the tilting base 58 ofthe pivotable mast vernier elevation and rotation unit 42 pivots aboutthe tilting base bearings 56 so that in effect the mast 28 may bepivoted about an axis through the bearings 56.

After the mast 28 is properly positioned with respect to a particularreactor internal to be examined such as a core stabilizing lug 36, corestop 38, or vessel cladding, the TV camera 132 is turned on so that theviewing angle A thereof is positioned to view the desired in ternal.Tilting for the purpose of viewing the top or bottom of a particularinternal is accomplished by actuation of the air cylinders 114 byselective admission of air through lines 116 to the cylinders 114. Byadjusting the lengths of the piston rods 118, the directional controlarm will be tilted to the right or left so as to alter the angle betweenthe actuating arm 122 and the pivoting arm 128 to pivot the camera 132about point for proper camera orientation, With the camera 132 properlypositioned, viewing may be undertaken with any necessary adjustments inthe angular position of the camera or its elevational or rotationalposition to increase the viewing range thereof being readilyaccomplished from the remote position above the reactor vault. Forexample, if it is desired to view the weld of the core stabilizing lug36 to the pressure vessel 12 along its entire length, the elevation ofthe camera 132 may be continually adjusted while the examination processis continuing. In a similar manner the other internals may be examined,the remote visual examination apparatus being moved in turn to desiredsuccessive access holes 32 around the core support barrel flange 34.

From the foregoing it is apparent that there is herein provided a remotevisual examination apparatus 10 for remote visual examination of reactorinternals, while the internals remain within vessel 12, both before andafter exposure to radiation. The operation is completely remote andcapable of being used in extremely small spaces at distances andgeometries which preclude the use of conventional optical systems suchas borescopes, perioscopes, and fiberoptics. The pivotablemast vernierelevation and rotation unit 42 affords precise positioning and controlfor extended viewing by pneumatically tiltable right angle head TVcamera 132 having a self-contained light source. Additionally, the Hconfiguration of the remote visual examination mast 28 affordsflexibility of the mast in one plane and rigidity in the other so as toprovide protection for air lines 116 (used in controlling the tilting ofthe TV camera 132) and the TV cable 140 while permitting horizontalmovement of the mast about a pivot axis just above the core supportbarrel flange 34.

It will be understood that various changes in the details, materials,and arrangements of parts which have been herein described andillustrated in order to explain the nature of the invention, may be madeby those skilled in the art within the principle and scope of theinvention as expressed in the appended claims.

What is claimed is:

1. A remote visual examination apparatus for viewing nuclear reactorinternals comprising:

a longitudinally extending mast manipulatable from one end;

a remotely operable optical viewing system;

means adjustably mounting said optical viewing system on said mast atthe end opposite the manipulated end; and

a remotely operable pivotable mast vernier elevation and rotation unitpositionable within the reactor, said pivotable mast vernier unitengagable with said mast for independently adjusting the axial positionof said mast along and the rotational positioning of said mast about itslongitudinal axis, and said vernier unit further including meanspermitting pivotable movement of said mast relative to said pivotablemast vernier unit so that said end of said mast opposite saidmanipulatable end moves in a direction generally perpendicular to thedirection of said longitudinal axis.

2. The apparatus of claim 1 wherein said longitudinally extending mastis of an H configuration having broad sides interconnected by a web soas to provide structural rigidity in a first lateral direction andstructural flexibility in a second lateral direction.

3. The apparatus of claim 2 wherein said remotely operable opticalviewing system includes a TV camera having a self-contained light systemand remote focus, the nose of said TV camera being of a bullet shape tofacilitate the insertion thereof within the reactor cavity.

4. The apparatus of claim 3 wherein said TV camera is provided with aside opening to provide right angle viewing.

5. The apparatus of claim 2 wherein said means for adjustably mountingsaid optical viewing system includes an extension means fixed to the endof said mast, pneumatic cylinder means positioned within said extensionmeans, a pivoted linkage system connected at one end to said pneumaticcylinder means and at said opposite end to said optical viewing systemwhereby actuation of said pneumatic cylinder means will control theviewing angle of said optical viewing system.

6. The apparatus of claim 5 wherein said extension means includes spacedelongated side plates, one plate fixed to each broad side of said mast,said side plates having slots along a portion of the length thereof; andwherein said pivoted linkage system includes a tilt directional controlarm having pins extending laterally therefrom, said pins riding in saidside plate slots, actuating arm means fixed to said directional controlarm for movement therewith, and pivoting arm means fixed at one end tosaid optical viewing system and pivotably.

connected at the opposite end to said actuating arm means, said pivotingarm means pivotably connected at an intermediate point to said sideplates.

7. The apparatus of claim 2 wherein said remotely operable pivotablemast vernierelevation and rotation unit includes a base, ball castersfixed to the underside of said base to permit lateral adjustment of saidunit, the rotational base supported by said first mentioned base, meansfor selectively rotating said rotational base, and means for selectivelyadjusting the axial positioning of said longitudinally extending mast,and wherein said means permitting pivotable movement of said mastrelative to said pivotable mast vernier unit comprises pivot supportbearings fixed to said rotational base and a tilting base supported onsaid pivot support bearings.

8. The apparatus of claim 7 wherein said means for rotating saidrotating base includes a remotely operable actuating gear, a gearassembly actuated by said actuating gear, a drive sprocket rotated bysaid gear assembly, a chain sprocket fixed to said rotating base, and achain interconnecting said drive sprocket and said chain sprocket.

9. The apparatus of claim 7 wherein said means for selectively adjustingthe axial positioning of said longitudinally extending mast is mountedon said tilting base and includes a remotely operable actuating gear, agear assembly actuated by said actuating gear and having a spur gear asthe final element thereof, and a rack fixed to said longitudinallyextending mast, said rack being engaged by said spur gear.

10. The apparatus of claim 9 wherein said remotely operable pivotablemast vernier elevation and rotation unit also includes means mounted onsaid tilting base for laterally supporting said longitudinally extendingmast.

Disclaimer 3,764,736.-Ri0hmd P. Kosky, East Granby, 001111., and PrestonW. A'uem'lt, Jn, Springfield, Mass. REMOTE VISUAL EXAMINATION AP-PARATUS. Patent dated Oct. 9, 1973. Disclaimer filed Aug. 30, 197 by theassignee, Combustion Engineem'ng, Inc. Hereby enters this disclaimer toclaim 1 of said. patent.

[Ofiiez'al Gazette N owembei" 12,1974]

1. A remote visual examination apparatus for viewing nuclear reactorinternals comprising: a longitudinally extending mast manipulatable fromone end; a remotely operable optical viewing system; means adjustablymounting said optical viewing system on said mast at the end oppositethe manipulated end; and a remotely operable pivotable mast vernierelevation and rotation unit positionable within the reactor, saidpivotable mast vernier unit engagable with said mast for independentlyadjusting the axial position of said mast along and the rotationalpositioning of said mast about its longitudinal axis, and said vernierunit further including means permitting pivotable movement of said mastrelative to said pivotable mast vernier unit so that said end of saidmast opposite said manipulatable end moves in a direction generallyperpendicular to the direction of said longitudinal axis.
 2. Theapparatus of claim 1 wherein said longitudinally extending mast is of anH configuration having broad sides interconnected by a web so as toprovide structural rigidity in a first lateral direction and structuralflexibility in a second lateral direction.
 3. The apparatus of claim 2wherein said remotely operable optical viewing system includes a TVcamera having a self-contained light system and remote focus, the noseof said TV camera being of a bullet shape to facilitate the insertionthereof within the reactor cavity.
 4. The apparatus of claim 3 whereinsaid TV camera is provided with a side opening to provide right angleviewing.
 5. The apparatus of claim 2 wherein said means for adjustablymounting said optical viewing system includes an extension means fixedto the end of said mast, pneumatic cylinder means positioned within saidextension means, a pivoted linkage system connected at one end to saidpneumatic cylinder means and at said opposite end to said opticalviewing system whereby actuation of said pneumatic cylinder means willcontrol the viewing angle of said optical viewing system.
 6. Theapparatus of claim 5 wherein said extension means includes spacedelongated side plates, one plate fixed to each broad side of said mast,said side plates having slots along a portion of the length thereof; andwherein said pivoted linkage system includes a tilt directional controlarm having pins extending laterally therefrom, said pins riding in saidside plate slots, actuating arm means fixed to said directional controlarm for movement therewith, and pivoting arm means fixed at one end tosaid optical viewing system and pivotably connected at the opposite endto said actuating arm means, said pivoting arm means pivotably connectedat an intermediate point to said side plates.
 7. The apparatus of claim2 wherein said remotely operable pIvotable mast vernier elevation androtation unit includes a base, ball casters fixed to the underside ofsaid base to permit lateral adjustment of said unit, the rotational basesupported by said first mentioned base, means for selectively rotatingsaid rotational base, and means for selectively adjusting the axialpositioning of said longitudinally extending mast, and wherein saidmeans permitting pivotable movement of said mast relative to saidpivotable mast vernier unit comprises pivot support bearings fixed tosaid rotational base and a tilting base supported on said pivot supportbearings.
 8. The apparatus of claim 7 wherein said means for rotatingsaid rotating base includes a remotely operable actuating gear, a gearassembly actuated by said actuating gear, a drive sprocket rotated bysaid gear assembly, a chain sprocket fixed to said rotating base, and achain interconnecting said drive sprocket and said chain sprocket. 9.The apparatus of claim 7 wherein said means for selectively adjustingthe axial positioning of said longitudinally extending mast is mountedon said tilting base and includes a remotely operable actuating gear, agear assembly actuated by said actuating gear and having a spur gear asthe final element thereof, and a rack fixed to said longitudinallyextending mast, said rack being engaged by said spur gear.
 10. Theapparatus of claim 9 wherein said remotely operable pivotable mastvernier elevation and rotation unit also includes means mounted on saidtilting base for laterally supporting said longitudinally extendingmast.